1. Java Debugging in Eclipse by Dr. Bun Yue Professor of Computer Science yue@uhcl.edu http://sce.uhcl.edu/yue/ 2013 yue@uhcl.edu http://sce.uhcl.edu/yue/ CSCI 3333 Data Structures

2. General Resources  Like other IDE, Eclipse includes a good debugger for Java.  Allows developers to control program execution for investigation.  http://help.eclipse.org/juno/index.js p: check the section on debugging. http://help.eclipse.org/juno/index.js p

3. Java Editor  The editor already provides assistance in program development and debugging.

4. Example

5. Perspective

6. Debugging  Likes solving mystery and puzzles, CSI, etc.  You need to have: 1. Domain knowledge 2. Reasoning 3. Investigating and looking for clues 4. Making and testing hypothesis  A debugger can help in (3) and (4).

7. Java Debugging  To debug a Java program, use one of the following: the debug button Run > Debug As > Java Application After confirmation, a debug perspective (view) is open. You can check variable values during program suspension by breakpoints.

8. Breakpoints  Can be used to suspend program execution.  Developers can then check variable values.  Can be disabled.

9. Example

11. Variable view

12. Actions after halted  Examples: Step into, Skip all breakpoints, Step Return, drop to frame, etc.

13. Method breakpoint

14. Watchpoint  A watchpoint is used to watch a variable.  The debugger halts when the variable is accessed.  You can toggle a watchpoint on a variable by right-clicking the declaration line of the variable.

15. Hit Count

16. More tips  More features and tips from http://javapapers.com/core- java/top-10-java-debugging-tips- with-eclipse/. E.g. http://javapapers.com/core- java/top-10-java-debugging-tips- with-eclipse/ Watch points Conditional breakpoints …  Video tutorial: http://eclipsetutorial.sourceforge.ne t/debugger.html http://eclipsetutorial.sourceforge.ne t/debugger.html

17. More tutorial  http://www.vogella.com/articles/Ecl ipseDebugging/article.html http://www.vogella.com/articles/Ecl ipseDebugging/article.html

18. Questions and Comments?